1. Field of the Invention
The present invention relates to an image forming apparatus, an image forming system, and an image forming method.
2. Description of the Related Art
Conventionally, an image forming apparatus in which clear toner that is colorless toner without color material is mounted besides toners of four colors of CMYK has been available. A toner image that is formed with such clear toner is fixed on a recording medium, such as a transfer sheet, on which an image has been formed with CMYK toner. As a result, a visual effect or a tactile effect (referred to as surface effect) are produced on a surface of the recording medium. The surface effect to be produced varies depending on what kind of toner image is formed with clear toner and how the image is fixed. The surface effect can be of simply giving a gloss, or of reducing a gloss. Moreover, not just giving a surface effect on an entire surface, a surface effect of giving the effect only on a part of a surface, or a surface effect of giving a texture or a watermark is also demanded. Furthermore, surface protection can be demanded. Moreover, there is a surface effect that is produced by performing postprocessing by a dedicated postprocessor such as a glosser and a low-temperature fuser, besides a fixation control. In recent years, a technique in which clear toner is fixed only on a desirable portion in a part of a surface to give a gloss has been developed.
Furthermore, in Japanese Patent Application Laid-open No. 2012-37618, an image forming apparatus has been disclosed that forms an image (overprinting) using clear toner on a recording material (sheet) on which color toner, or color toner and clear toner have been fixed.
However, there has been a problem that if overprinting is performed to produce a high-gloss effect (mirror finish and the like), the glossiness increases even in a region in which a low gloss effect (matt finish) is to be produced.
In view of the above problem, there is a need to provide an image forming apparatus, an image forming system, and an image forming method by which an image can be formed, appropriately giving a surface gloss effect for each of image regions indicated by image data.